More and more goods and services are purchased electronically today by the aid of electronic communication devices. Such communication devices are computers with an on-line connection or stationary or mobile (cellular) phones. When using a modern cellular phone, the user/customer has the choice of dialling the telephone number of a provider offering goods and/or services in order to talk to the provider in person via a voice channel, or to build up an internet connection in order to place his purchase order on the website of the provider.
A very important cellular standard network is the so-called GSM (Groupe Spécial Mobile/Global system for mobile communications). Mobile stations under the GSM comprise the mobile equipment (cellular phone) itself and a so-called subscriber identity module (SIM), the latter essentially consisting in a GSM specific chip card. The function of the SIM consists in ensuring that only authorized persons obtain access to the net, thus securing an operating call metering. To achieve this goal, the SIM securely stores user specific data (international mobile subscriber identity—IMSI) and executes a cryptographic algorithm under secure conditions.
A very common method of payment in electronic business transactions consists in that the customer gives his credit card particulars to the provider. The provider then verifies the credit card data and, upon positive authentication of the data, delivers the purchased goods or services. However, because of the high risk of fraud when passing on credit card particulars via a relatively open network to unknown persons, a lot of users deter from this method of payment.
Another known method of payment involves the use of smart cards which overcome the drawback of the danger of fraud, but which often fails due to the missing public key infrastructure and a lack of customer acceptance.
With the increasing importance of electronic commerce and electronically transacted purchasing actions, there is in fact a high need of a secure and commonly acceptable payment method.